How do I get him to choose me over his ex?

So this guy i like still likes me back but today he told me tht he still had feelings for me but he is in a place right now and he doesn't know what he wants. He doesn't know tht i know he's deciding between me nd his ex... he told me tht i was perfect and beautiful to him nd he didn't want me to move on. His ex has a boyfriend, she's a slut nd sleeps with everyone, he always flashes her boobs at people, she cheated on my crush more than 5 times, she's a player, she's just bad news... I dont want him going back out with her cuz i dont want to see him hurt again because he made the wrong decision again. Im scared tht he is still toooooo in love with his ex nd tht he won't chose me. They broke up 2 years ago so idky he's still wanting her back. I would think he had moved on from her. Ik he would make the right choice if he picked me over her because i am NOTHING ABSOLUTELY NOTHING like his ex. I feel like he's hesitant about me cuz i am too loyal? I don't know but what should i do to keep his eyes on me nd to make him fall more for me than think about his ex? My decision at the moment was to let him think about it and have him take his time.